RESEARCH Assessment of SPLAT formulations to control Grapholita molesta (Lepidoptera: Tortricidae) in a Brazilian apple orchard Cristiano João Arioli1, Patrik Luiz Pastori2*, Marcos Botton3, Mauro Silveira Garcia4, Rafael Borges5, and Agenor Mafra-Neto5 Mating disruption is a technique that uses synthetic copies of sex pheromones to control insect pests. We aimed to control Oriental fruit moth (OFM) Grapholita molesta (Busck) (Lepidoptera: Tortricidae) with formulations of SPLAT Grafo (SG) and SPLAT Grafo Attract and Kill (SGAK) in small (1 ha) apple (Malus domestica Borkh.) orchards. Our experiment was conducted in a commercial orchard with ‘Gala’ trees (spacing 1.5 × 4.5 m) in Vacaria, Rio Grande do Sul State, Brazil. We evaluated the effect of four treatments on G. molesta population densities: a) SG at 1 kg ha-1 (300 point sources of 3.3 g each), b) SGAK at 1 kg ha-1 (1000 point sources of 1 g each), c) insecticides as recommended by Integrated Apple Production (IAP), and d) untreated control (no treatment). Specialized Pheromone and Lure Application Technology (SPLAT) treatments were applied on 1 August 2004 and reapplied after 120 d (1 December 2004). The treatment effect was evaluated by weekly counts of males captured in Delta traps baited with commercial synthetic sex pheromone lures (eight traps per treatment). We assessed fruit damage caused by G. molesta in eight replicates of 200 fruits each on 26 October, 30 November 2004, and 5 and 31 January 2005. Applying 1 kg ha-1 of SG and SGAK in August and December 2004 significantly reduced the number of male moths caught in Delta traps. Damage to fruits at harvest, however, did not differ significantly from the control. This indicates a decline in the efficacy of mating disruption when SG and SGAK are used to protect small areas (1 ha) under high Oriental fruit moth pressure. Key words: Attract and kill, integrated apple production, Malus domestica, Oriental fruit moth, pheromone trap. INTRODUCTION Damage caused by OFM is the result of larval feeding in both shoots and fruits (Kovaleski and Ribeiro, 2003). Oriental fruit moth (OFM) Grapholita molesta (Busck) Feeding larvae undermine the formation of new shoot (Lepidoptera: Tortricidae) is a major pest of stone fruits growth and will destroy newly forming flower buds. The (Salles and Marini, 1989; Botton et al., 2005), which OFM larvae preferentially feed near the stem of the fruit, specifically causes substantial damage to apple orchards in thus penetrating and causing damage near the calyx. This Brazil (Kovaleski and Ribeiro, 2003; Pastori et al., 2008; results in impaired fruit with internal galleries that may 2012). Damage by G. molesta has been frequently reported still contain live larvae after harvest. Damaged fruit has in stone fruits and apples in the three major fruit-producing little or no market value, and its presence in shipments regions of Southern Brazil (Fraiburgo and São Joaquim in may preclude export (Pastori et al., 2008; Neto and Silva Santa Catarina State and Vacaria in Rio Grande do Sul State). et al., 2010). Grapholita molesta populations have been suppressed primarily with broad-spectrum insecticides, mainly 1 Empresa de Pesquisa Agropecuária e Extensão Rural do Estado de organophosphates (Kovaleski and Ribeiro, 2003). They Santa Catarina, Estação Experimental de São Joaquim, 88.600-000, São Joaquim, Santa Catarina, Brasil. are highly toxic and deleterious to non-target organisms, 2Universidade Federal do Ceará, Centro de Ciências Agrárias, such as natural enemies (Manzoni et al., 2006; Moura et 60.356-000, Fortaleza, Ceará, Brasil. al., 2012) and pollinators (Pinheiro and Freitas, 2010). *Corresponding author ([email protected]). Moreover, the long pre-harvest interval for the main 3 Empresa Brasileira de Pesquisa Agropecuária Embrapa, Centro conventional insecticides recommended in the Integrated Nacional de Pesquisa Uva e Vinho, 95.700-000, Bento Gonçalves, Apple Production (IAP) (Kovaleski and Ribeiro, 2003) Rio Grande do Sul, Brasil. 4Universidade Federal de Pelotas, Faculdade de Agronomia Eliseu limits their use during the harvest period (Pastori et al., Maciel, 96.160-000, Capão do Leão, Rio Grande do Sul, Brasil. 2008) when OFM populations are high. Significant fruit 5ISCA Technologies, Inc., 1230 Spring Street, Riverside, California damage (up to 40%) caused by OFM has been observed A 92507, USA. mainly in areas with late-maturing varieties of apples. Received: 8 July 2013. Therefore, interest has drastically increased in the Accepted: 3 April 2014. doi:10.4067/S0718-58392014000200009 development of alternatives that effectively control G. 184 CHILEAN JOURNAL OF AGRICULTURAL RESEARCH 74(2) APRIL-JUNE 2014 CHILEAN JOURNAL OF AGRICULTURAL RESEARCH 74(2) APRIL-JUNE 2014 185 molesta, while remaining consistent with market standards (300 point sources of 3.3 g each), b) SPLAT Grafo Attract (Joshi et al., 2011). Using synthetic sex pheromones and Kill (SGAK) at a rate of 1 kg ha-1 (1000 point sources to interfere with mating and reproduction offers a non- of 1 g each), c) Integrated Apple Production (IAP) using traditional way to manage pests before using conventional the insecticide regime recommended by IAP (Protas, insecticides (Larraín et al., 2009). 2003), and d) untreated control. The SPLAT treatments Control of OFM through mating disruption has been were uniformly distributed in the experimental units, successful worldwide (Rothschild, 1975; Vilcker et al., while the borders received an additional 10% application 1985; Molinari et al., 2000; Trimble et al., 2001; Kovanci of SPLAT to decrease ‘edge effect’ (Molinari, 2002). The et al., 2005a), including promising results in Brazil (Salles following insecticides were applied to the IAP-treated and Marini, 1989; Botton et al., 2005; Monteiro et al., experimental unit: Fenitrothion (Sumithion 500 CE®, 2008; Pastori et al., 2008; 2012). A range of commercial 150 mL 100 L-1) applied on 25 October, 6 November, semiochemical mating disruption products is available and 22 December 2004, and 17 January 2005 to control to control G. molesta. These products come in a variety G. molesta. Phosmet (Imidan 500®, 120 g 100 L-1) was of formulations, including sachets, ropes, and twist applied on 18 November 2004 to control G. molesta ties (Degen et al., 2005). Semiochemical formulations and Anastrepha fraterculus (Wiedemann) (Diptera: generally differ in both their longevity and implementation Tephritidae). Methidathion (Supracid 400®, 100 mL cost (Lame et al., 2010; Bohnenblust et al., 2011). Solid 100 L-1) was applied on 26 November and 9 December dispensers are hung on plants manually, which requires 2004 to control G. molesta, Bonagota salubricola a substantial amount of labor for field application. One (Meyrick) (Lepidoptera: Tortricidae), and A. fraterculus. alternative is to use liquid microencapsulated pheromone All experimental units were under the same cultural formulations that can be mixed in water and applied as management. sprays with the same equipment for spraying insecticides. These methods have short longevity in the field and Formulation of synthetic sex pheromone and therefore require frequent reapplication (Trimble et al., application method 2004; Botton et al., 2005; Kovanci et al., 2005b). The SPLAT Grafo formulation contained (Z)-8-dodecenyl SPLAT (Specialized Pheromone and Lure Application acetate, (E)-8-dodecenyl acetate, and (Z)-8-dodecenol (44 Technology) (ISCA Technologies, Inc., Riverside, g kg-1), while SPLAT Grafo Attract and Kill contained California, USA) is a waxy, flowable matrix (Atterholt (Z)-8-dodecenyl acetate, (E)-8-dodecenyl acetate, et al., 1999; Mafra-Neto, 2010; Pastori et al., 2012) (Z)-8-dodecenol (22 g kg-1), and (RS)-alpha-cyano-3- that allows the incorporation of varying concentrations phenoxybenzyl (1RS)-cis-, trans-3-(2,2-dichlorovinyl)- of pheromone and/or insecticide in the formulation 2,2-dimethylcyclopropane carboxylate (Cypermethrin) (Stelinski et al., 2005). SPLAT can be applied manually (50 g kg-1). or mechanically in the field as discrete point sources, Two applications of each SPLAT formulation were which, along with variable size and density of deposits, made on 1 August and 1 December 2004 to control all provides semiochemical control that is tailored to this the generations of G. molesta during the season. The field (Stelinski et al., 2005). SPLAT point sources were distributed manually in the The purpose of this study was to determine the experimental units with wooden spatulas previously effectiveness of SPLAT Grafo (SG) and SPLAT Grafo calibrated to deliver either 1.0- or 3.3-g sized dollops. Attract and Kill (SGAK) to manage G. molesta in small The point sources were placed at the base of the branches areas (1 ha) of Brazilian apple orchards. at 1.5 to 2.0 m above the soil surface, while SPLAT was completely shaded from the sun. MATERIALS AND METHODS Efficiency of treatments Experimental area and treatments Treatment evaluations were performed by recording The experiment was conducted from July 2004 to January captures of male G. molesta in Delta traps baited with 2005 (2004-2005 growing season) in Vacaria, Rio Grande the synthetic sex pheromone. Inspection of fruit at do Sul State, Brazil. Field trials took place in a ‘Gala’ harvest allowed us to determine if damage was caused apple (Malus domestica Borkh.) orchard established in by G. molesta, the Brazilian apple leafroller (Bonagota 1990. Spacing was 1.5 × 4.5 m (rows × plants) and trees salubricola), another Lepidoptera (Geometridae were 3.5 to 4.0 m tall. and Noctuidae), or the South American fruit fly (A. Four experimental units (EUs) were established, fraterculus). each consisting of 1.0 ha subdivided into four plots or Standard 28 × 20 cm white plastic Delta traps (ISCA replicates of 0.25 ha. A distance of 10 m separated each Technologies Ltda., Ijuí, Rio Grande do Sul, Brazil) baited plot; the experiment had a fully randomized design. Each with ISCAlure Grafolita® (ISCA Technologies Ltda., Ijuí, experimental unit was assigned one of the following Rio Grande do Sul, Brazil) were used to monitor the male treatments: a) SPLAT Grafo (SG) at a rate of 1 kg ha-1 G.